The invention proceeds from a pump, in particular a high-pressure fuel pump.
Such a pump in the form of a high-pressure fuel pump is disclosed by DE 10 2010 063 363 A1. This pump comprises a pump element having a roller tappet, via which a pump piston is supported on a cam of a drive shaft. In the roller tappet a roller, which bears on the cam, is rotatably supported on a bearing pin. The roller is supported on the bearing pin by way of a bearing bush. The bearing bush usually comprises a body composed of metal, in particular steel, which is provided with a coating of friction-bearing material. The highly accurate machining required and the application of the coating make manufacturing of the bearing bush very exacting. In addition, an uneven pressure distribution can occur in the bearing bush between this and the roller and/or the bearing pin, resulting in greater pressures in the edge areas of the bearing bush, so that increased wearing of the bearing bush occurs in these areas. The known steel bearing bushes have only poor emergency running characteristics in the event of inadequate lubrication, so that in this case heavy wearing of the bearing bush and/or the roller and/or the bearing pin can occur.